// This file is part of Eigen, a lightweight C++ template library
// for linear algebra.
//
// Copyright (C) 2014 Benoit Steiner <benoit.steiner.goog@gmail.com>
//
// This Source Code Form is subject to the terms of the Mozilla
// Public License v. 2.0. If a copy of the MPL was not distributed
// with this file, You can obtain one at http://mozilla.org/MPL/2.0/.

#include "main.h"

#include <Eigen/CXX11/Tensor>

using Eigen::Tensor;

template<int DataLayout>
static void
test_simple_patch()
{
	Tensor<float, 4, DataLayout> tensor(2, 3, 5, 7);
	tensor.setRandom();
	array<ptrdiff_t, 4> patch_dims;

	patch_dims[0] = 1;
	patch_dims[1] = 1;
	patch_dims[2] = 1;
	patch_dims[3] = 1;

	Tensor<float, 5, DataLayout> no_patch;
	no_patch = tensor.extract_patches(patch_dims);

	if (DataLayout == ColMajor) {
		VERIFY_IS_EQUAL(no_patch.dimension(0), 1);
		VERIFY_IS_EQUAL(no_patch.dimension(1), 1);
		VERIFY_IS_EQUAL(no_patch.dimension(2), 1);
		VERIFY_IS_EQUAL(no_patch.dimension(3), 1);
		VERIFY_IS_EQUAL(no_patch.dimension(4), tensor.size());
	} else {
		VERIFY_IS_EQUAL(no_patch.dimension(0), tensor.size());
		VERIFY_IS_EQUAL(no_patch.dimension(1), 1);
		VERIFY_IS_EQUAL(no_patch.dimension(2), 1);
		VERIFY_IS_EQUAL(no_patch.dimension(3), 1);
		VERIFY_IS_EQUAL(no_patch.dimension(4), 1);
	}

	for (int i = 0; i < tensor.size(); ++i) {
		VERIFY_IS_EQUAL(tensor.data()[i], no_patch.data()[i]);
	}

	patch_dims[0] = 2;
	patch_dims[1] = 3;
	patch_dims[2] = 5;
	patch_dims[3] = 7;
	Tensor<float, 5, DataLayout> single_patch;
	single_patch = tensor.extract_patches(patch_dims);

	if (DataLayout == ColMajor) {
		VERIFY_IS_EQUAL(single_patch.dimension(0), 2);
		VERIFY_IS_EQUAL(single_patch.dimension(1), 3);
		VERIFY_IS_EQUAL(single_patch.dimension(2), 5);
		VERIFY_IS_EQUAL(single_patch.dimension(3), 7);
		VERIFY_IS_EQUAL(single_patch.dimension(4), 1);
	} else {
		VERIFY_IS_EQUAL(single_patch.dimension(0), 1);
		VERIFY_IS_EQUAL(single_patch.dimension(1), 2);
		VERIFY_IS_EQUAL(single_patch.dimension(2), 3);
		VERIFY_IS_EQUAL(single_patch.dimension(3), 5);
		VERIFY_IS_EQUAL(single_patch.dimension(4), 7);
	}

	for (int i = 0; i < tensor.size(); ++i) {
		VERIFY_IS_EQUAL(tensor.data()[i], single_patch.data()[i]);
	}

	patch_dims[0] = 1;
	patch_dims[1] = 2;
	patch_dims[2] = 2;
	patch_dims[3] = 1;
	Tensor<float, 5, DataLayout> twod_patch;
	twod_patch = tensor.extract_patches(patch_dims);

	if (DataLayout == ColMajor) {
		VERIFY_IS_EQUAL(twod_patch.dimension(0), 1);
		VERIFY_IS_EQUAL(twod_patch.dimension(1), 2);
		VERIFY_IS_EQUAL(twod_patch.dimension(2), 2);
		VERIFY_IS_EQUAL(twod_patch.dimension(3), 1);
		VERIFY_IS_EQUAL(twod_patch.dimension(4), 2 * 2 * 4 * 7);
	} else {
		VERIFY_IS_EQUAL(twod_patch.dimension(0), 2 * 2 * 4 * 7);
		VERIFY_IS_EQUAL(twod_patch.dimension(1), 1);
		VERIFY_IS_EQUAL(twod_patch.dimension(2), 2);
		VERIFY_IS_EQUAL(twod_patch.dimension(3), 2);
		VERIFY_IS_EQUAL(twod_patch.dimension(4), 1);
	}

	for (int i = 0; i < 2; ++i) {
		for (int j = 0; j < 2; ++j) {
			for (int k = 0; k < 4; ++k) {
				for (int l = 0; l < 7; ++l) {
					int patch_loc;
					if (DataLayout == ColMajor) {
						patch_loc = i + 2 * (j + 2 * (k + 4 * l));
					} else {
						patch_loc = l + 7 * (k + 4 * (j + 2 * i));
					}
					for (int x = 0; x < 2; ++x) {
						for (int y = 0; y < 2; ++y) {
							if (DataLayout == ColMajor) {
								VERIFY_IS_EQUAL(tensor(i, j + x, k + y, l), twod_patch(0, x, y, 0, patch_loc));
							} else {
								VERIFY_IS_EQUAL(tensor(i, j + x, k + y, l), twod_patch(patch_loc, 0, x, y, 0));
							}
						}
					}
				}
			}
		}
	}

	patch_dims[0] = 1;
	patch_dims[1] = 2;
	patch_dims[2] = 3;
	patch_dims[3] = 5;
	Tensor<float, 5, DataLayout> threed_patch;
	threed_patch = tensor.extract_patches(patch_dims);

	if (DataLayout == ColMajor) {
		VERIFY_IS_EQUAL(threed_patch.dimension(0), 1);
		VERIFY_IS_EQUAL(threed_patch.dimension(1), 2);
		VERIFY_IS_EQUAL(threed_patch.dimension(2), 3);
		VERIFY_IS_EQUAL(threed_patch.dimension(3), 5);
		VERIFY_IS_EQUAL(threed_patch.dimension(4), 2 * 2 * 3 * 3);
	} else {
		VERIFY_IS_EQUAL(threed_patch.dimension(0), 2 * 2 * 3 * 3);
		VERIFY_IS_EQUAL(threed_patch.dimension(1), 1);
		VERIFY_IS_EQUAL(threed_patch.dimension(2), 2);
		VERIFY_IS_EQUAL(threed_patch.dimension(3), 3);
		VERIFY_IS_EQUAL(threed_patch.dimension(4), 5);
	}

	for (int i = 0; i < 2; ++i) {
		for (int j = 0; j < 2; ++j) {
			for (int k = 0; k < 3; ++k) {
				for (int l = 0; l < 3; ++l) {
					int patch_loc;
					if (DataLayout == ColMajor) {
						patch_loc = i + 2 * (j + 2 * (k + 3 * l));
					} else {
						patch_loc = l + 3 * (k + 3 * (j + 2 * i));
					}
					for (int x = 0; x < 2; ++x) {
						for (int y = 0; y < 3; ++y) {
							for (int z = 0; z < 5; ++z) {
								if (DataLayout == ColMajor) {
									VERIFY_IS_EQUAL(tensor(i, j + x, k + y, l + z),
													threed_patch(0, x, y, z, patch_loc));
								} else {
									VERIFY_IS_EQUAL(tensor(i, j + x, k + y, l + z),
													threed_patch(patch_loc, 0, x, y, z));
								}
							}
						}
					}
				}
			}
		}
	}
}

EIGEN_DECLARE_TEST(cxx11_tensor_patch)
{
	CALL_SUBTEST(test_simple_patch<ColMajor>());
	CALL_SUBTEST(test_simple_patch<RowMajor>());
	//   CALL_SUBTEST(test_expr_shuffling());
}
